The C.P. where I did my Instructors course found himself with a cracked crankshaft shortly after take off with nothing but a housing estate ahead. He performed a Turn-Back getting it back into the field, albeit not on the runway, with both occupants walking away. He was ex-C.F.S. but has been out for years.
I can see it being a fine line and one I always thought was a definate no-no but my mind has been changed and I will be trying it out at height.
Partly because of above story and partly due to visiting a certain field in Kent today. It wasn't until 800' off R02 did I feel we would stand a chance of clearing the houses and preverbial Primary School!!